This invention relates to rearview mirror assemblies for vehicles and, more particularly, to rearview mirror assemblies in which light sources are provided for illumination of interior portions of the vehicle in which the assembly is mounted.
Vehicles with conventional, permanent tops or roofs can easily provide interior map and/or courtesy lighting from the roof area via dome lights or the like which shine downwardly and forwardly or rearwardly over the shoulders of the driver or passengers to enable the reading of maps, books or the like, as well as to light the interior when entering the vehicle. However, in vehicles with removable tops including convertibles, off-road vehicles, or vehicles having removable sunroofs, the conventional practice of providing interior lighting from the roof area of the vehicle interior is difficult or impossible to accomodate.
One solution to interior lighting in such vehicles is to provide lighting from the typical rearview mirror location at the windshield header in the vehicle. Lighted rearview mirror assemblies such as those shown in Canadian Pat. No. 551,492 and in U.S. Pat. No. 3,543,018 have been devised previously to provide interior lighting from such vehicle areas. In Canadian Pat. No. 551,492, a hollow box-like structure is disclosed having a rearwardly facing mirror glass supported adjacent a pair of light bulbs mounted within the interior of the box. The generated light shines downwardly through a translucent panel fitted along the bottom of the box or housing.
In U.S. Pat. No. 3,543,018, a single light bulb is positioned in a laterally shiftable manner within a metallic mirror case through the bottom of the case. The case conducts electricity and serves as a ground connection to complete the circuit through the bulb. A lens supported beneath the bulb on the shiftable support holding the bulb directs light downwardly when the shiftable support is moved into contact with the metallic mirror housing.
While such prior structures have provided a certain amount of light from the rearview mirror area, they do encompass a number of drawbacks. For example, the prior structures have tended to generate a great deal of heat from the light bulbs therewithin during use. That heat is transferred to the surrounding case creating hot spots on the case which can burn an unwary user of the light. Moreover, the quantity of light and the positioning of and direction of the light for use by either the driver or passengers within the car has been less than adequate with such structures. In addition, because of the weight of the metallic cases and the bulky light supporting structures in such prior structures, the overall weight of such assemblies has been relatively high. These factors contribute to a significant amount of vibration when the assemblies are in use in vehicles. The vibration reduces visibility in the mirror element in the assembly. Such reduced visibility can be a significant safety hazard to proper use of the rearview mirror which is the principal function of such assemblies.
A further problem encountered with prior structures of this type has been the leakage or misdirection of light toward the front of the vehicle in which the rearview mirror assembly is mounted. This causes illumination of instrument panel areas of the vehicle or other undesired areas. In addition, such structures have been prone to light leakage visible to the driver or passengers which, when coupled with illumination of undesired areas of the vehicle, can serve as a significant distraction to the driver or passenger thereby also creating a safety hazard.
In addition to the heat, light direction, vibration and light leakage problems mentioned above, prior structures of this type have been difficult to design in a compact, aesthetic and useful manner which avoids unnecessary bulk which can create a vision hazard to the driver or passengers of a vehicle.
Although a certain amount of light is provided from other types of structures such as lighted vanity mirrors incorporated in more recent vehicles manufactured in the U.S. and elsewhere, lighted vanity mirrors do not provide a solution to the problem of general interior and/or courtesy lighting for use for reading by the driver or passengers or the provision of courtesy lighting during entrance into the vehicle since they are primarily directed to illuminating the face of a person using the vanity mirror. Accordingly, lighted vanity mirrors also do not provide a solution to the interior lighting problems mentioned above.